Electrical switch apparatus



Jun 24, 1.930. D. R. FURNAS 1.168.245

ELECTRICAL SWITCH APPARATUS Filed Oct. '18, 1926 2 Sheets-Sheet 1 19 19 -fiurent5.

' v v 1/ 4 21 J1 I WthEe-s EZZ Patented June 24, 1930 UNITED STATES PATENT OFFICE DON ROSS FURNAS, OF AURORA, ILLINOIS, ASSIGNOR TO AURORA STEEL PRODUCTS COMPANY, OF AURORA, ILLINOIS, A CORPORATION OF ILLINOIS ELECTRICAL SWITCH APPARATUS Application filed October 18, 1926. Serial No. 142,289.

of the line. The fuse and switch are usually enclosed in a box-like housing, and the entire unit is commonly referred to as an A switch.

In this type of circuit protecting apparatus, the fuse must be accessible to the resident of the dwelling in order that be may replace the same in the event of blowing. It is now common practice, and in many localities it is required, that safety features be incorporated in this switch apparatus, whereby access cannot be had to the fuse until the associated switch has been opened to cut the fuse off the line. This is to prevent any possibility of a ground being accidentally 5 established, with consequent injury to the person replacing the fuse.

.The present invention is directed to improvements in devices of this class, and has as one of its objects to provide improved so closure means for normally obstructing ac cess to the fuse, and to correlate with this clo sure means improved interlocking mechanism whereby the closure means cannot be opened until the switch has been opened, and

: whereby the closing of the switch necessitates the closing of the closure means, either before or with the closing of the switch. Thus, at no time is the fuse accessible in a live condition. I

Further objects of the invention are to provide an improved construction of box or housing for supporting the fuse, switch, switch operating means and closure means; and to provide an improved construction and .e' arrzmgement of conduit connections cooperating with the box to connect adjacent boxes together.

In the accompanying drawings illustrating a preferred embodiment of my invention:

c Figure 1 is a front elevational view of the present switch devices arranged in a bank on the usual meter panel.

Fig. 2 is a vertical sectional view through one of these switch devices, showing the closure slide in its upper or closed position.

Fig. 3 is a similar fragmentary view showing the closure slide in its lower or open position.

Fig. 4 is a transverse sectional view taken approximately on the plane of the line 4.4 of Fig. 2.

Fg 5 is a perspective view of the closure slide.

Fig. 6 is a detail sectional View illustrating the interlocking joint between the conduit section and the switch box, this view corresponding to a section taken on the plane of the line 66 of Figure 1, and

Fig. 7 is a fragmentary perspective view of an end of one of the conduit sections.

Figure 1 illustrates a typical installation of my invention on a distributing panel such as would be found in the basement of an apartment, store, or the like, wnere a plurality of meters and A switches are grouped in bank for connection with a plurality of distributing circuits. The three meters 10 are each provided with a separate A switch 11, each of the latter being generally disposed directly below its particular meter and having a portion of its box-like housing embracing the terminal portion of the meter.

As will be hereinafter described in detail, the hinged front cover of each switch box is provided with an opening 19. through which access is afforded to the fuse 13, such opening being normally closed by a sliding closure plate. Contained within each switch box is a switch unit 15 which is included in circuit with the fuse mounting whereby the opening of such switch is operative to cut the fuse mounting off the line. The switch unit 15 is actuated through an operating handle 16 which is disposed at one side of the switch box, suitable indiciabeing placed on the box indicating the off and on positions of theswitch handle.

The switch apparatus illustrated to the left in Figure 1 shows the closure plate 14 in its open position with the fuse 13 exposed for access, it being noted that at this time the switch operating handle 16 is extended forwardly corresponding to its oil": position. The center switch apparatus in Figure 1 is illustrated 'ith its housing cover swung down to illustrate the general grouping of the parts inside the housing. The right hand switch unit illustrates the cover swung up in closed position, and the closure slide 1 in closed position, corresponding to the normal position of the parts.

Referring to Figs. 2, 3 and l, the box or housing is of metallic construction, consisting of a back wall 18, side walls 19 and top and bottom walls 21 and 22, the latter preferably consisting of flanged stan'ipings suitably bolted to the side walls 19. The front of the box is adapted to be closed by a swinging cover 23 which is preferably hinged to the bottom wall 22 of the box on suitable hinges 2st. This cover has extending marginal flanges 25 embracing the sides and ends of the box. The upper wall 21 of the box has an opening 26 cut therein for receiving the lower terminal portion 10 of the meter 10. By thus having the box embrace this terminal portion of the meter, as best shown in Fig. 2, the possibility of anyone gaining access to the terminal connections of the meter and thereby shunting or tapping the meter is effectively prevented. in apertured lug 27 is riveted to the side wall of the box and is adapted to extend through a slotted opening 28 in the cover for receiving a padlock or seal for preventing or indicating unauthorized opening of the switch box.

Located substantially centrally within the box, and secured to the back wall 18 thereof, is a combination fuse and switch block 31 constructed of porcelain or other suitable insulating material. A boss 32 projects forwardly from the upper end of this block, and secured therein is a threaded socket 33 which receives the conventional fuse plug 13. Obviously, other types of fuse mountings might be employed for receiving other types of fuses, but the construction illustrated is now in such standard practice that it is more typical of the preferred construction. The associated switch 15 which controls the line circuit through the fuse socket consists of a switch blade 31 mounted on a pivot lug 35 and adapted to engage with a contact lug 36, both of these lugs being suitably supported on the block 31. Suitable connecting terminals 37 are also mounted on the block for making the desired circuit connections hrough the switch and fuse, these circuit connections being well known and therefore not requiring any detailed description. A small secondary switch 38 may also be mounted on the block 31, this latter switch being provided for the purposes of meter testing and being so connected that the meter tester, by making the proper connections, and opening the switch, can place his testing meter in the proper circuit relation for calibrating the house meter 10.

The switch operating handle 16 comprises part. of a switch operating shaft 39 extending transversely through the casing and rotatably supported in the side walls 19 thereof (Fig. l). Intermediate these side walls, the shaft is formed with a crank portion l1 which engages in a slot 42 formed in the front edge of an arm 43 of insulating material, such as fibre, which arm is secured to and projects at right angles from the switch blade 3i. It will be obvious from this arrangement of parts that when the operat ing handle 16 is swung to an upwardly extending position the switch blade 34 will move into engagement with the contact lug 36, and that when the operating handle is swung down to approximately horizontal position, the switch blade will be moved out into its open position, both of these switch blade movements resulting from the motion of the crank portion 11 engaging in the slot 42. The switch operating shaft is preferably pivoted in the side walls of the housing on an axis which is approximately concentric with respect to the pivotal axis of the switch blade in its mounting in the pivot lug 35. Secured to the outer side of the switch box a stop lug ll against which the operating handle 16 is brought when the switch is moved to open position and such stop lug may be plOYldCtl with an aperture or otherise arranged for receiving a padlock when is desired to lock the switch in open position.

As previously mentioned, the opening 12, through which access is had to the fuse 1 is formed in the hinged cover 23, and such opening is adapted to be normally closed by a sliding closure plate 14:, which closure plate is suitably guided for sliding movement on the inner wall of the cover. Directly in back of the opening 12, the cover carries a spaced plate -16 havii g side flanges -17 (Fig. -1 which are riveted or spot-welded to the inner side of the cover. This rearwardly spaced back plate has a circular opening l8 punched therein which engages over and closely embraces the head of the fuse 13 when the cover is in closed position. Such back pla e forms the bottom or rear wall of a. compartment 4.) into which the bean of the fuse extends, the sliding closure plate 14; normally forming the front wall of this compartment. Upper and lower flanges 5151 cooperate with the side flanges 47 in completing the side walls of this compartment, such compartment serving the purpose of a. substantially closed partition for preventing any possibility of contact between ones fingers and the switch contacts or other live parts, in the operation of substituting a blown fuse.

Gil

The spaced plate 46 also functions as a guide for the sliding closure plate 14. As shown in Fig. 5, this closure plate has two rearwardly bent flanges 5252 which lie against the inner sides of the side flanges 47 of the back plate 46. The flanges 52 of the slide pass through slots 53 formed-at the ends of the upper and lower flanges 51-51, such slots also serving as guide surfaces for the slide. The upper edge of the closure slide has secured thereto an outwardly extending hook or tab 54 which servesas a handle, and as a detent member for holding the slide in its different positions. Secured to the outer side of the hinged cover (Fig. 2) is a spring detent 55 having a beaded or looped end 56. When the closure slide is moved upwardly to closed position the hook 54 snaps under the looped end of the spring detent, thereby holdingthe slide in its upper position against the action of gravity. To release the slide for movement toopen position it is merely necessary to raise the spring detent 55; in its open position the hook 54 engages the bottom edge of the opening 12 and prevents the slide from dropping down out of reach.

The movement of the slide to open position is made subject to the position of the switch blade 84 through an interlocking relation existing bet-ween the slide and the switch operating shaft 39. This interlocking relation is established through a lug 57 which is secured to the lower edge of the slide (Fig. 5) and which is arranged to have contact with the I crank portion of the switch operating shaft to one side of the insulating arm 43. Such lug has two right angle edge surfaces 57 and 57 which cooperate with the crank portion 41 to establish the aforesaid interlocking relation between the position of the slide and the position of the switch blade.

In the functioning of this interlocking mechanism, when the closure slide is up in its closed position and the switch is also in its closed position (Fig. 2), opening of the closure slide to gain access to a blown fuse cannot be accomplished as long as the switch remains in closed position, owing to the lower edge 57* of the lug 57 striking the crank portion 41 of the switch operating shaft. As soon, however, as this crank portion has been revolved downwardly to the position indicated in Fig. 3, this corresponding to the open position of the switch, the lug 57 is free to move over the crank portion 41, whereby the slide will drop to its 0 en position. blown fuse can now be su stituted with absolute safety as the complete disconnecting of the fuse socket from the line prevents any possibility of a ground being accidently established. Also, in thus substituting a fuse there is no possibility of ones fingers contacting with the switch parts or other live parts, owing to the complete protection afforded by therearwardly spaced partition wall 46.

The 63 After the new fuse has been placed in the fuse socket, the switch 15 cannot be closed without firstclosing the slide 14, which is desirable, otherwise the switch might be closed and the slide left open indefinitely. This latter interlocking function follows from the striking of the crank pbrtion 41 against the edge 57 of the stop lug 57 when it is attempted to close the switch before the slide has been closed. As soon as the slide is raised to closed position, the crank portion 41 can again be swung up to its switch closing position below the lower edge of the lug 57, in the position shown in Fig. 2. If the slide 14 is not raised completely to its closed position the continued upward movement of the crank portion 41 with the movement of the switch to closed position will force the slide, through the lug 57, up into its upper position and into latched engagement with the spring detent 55.

lVhere two or more of these A switches are grouped on a panel it is often times desirable to connect adjacent switch boxes with interconnecting sections of conduit in order that the wiring between adjacent boxes can be completely concealed, thereby minimizing the opportunities of tapping circuits, reducing the fire hazard, and improving the general appearances of the wiring layout. ()ne of the features of the present invention is to provide an improved arrangement and construction of conduit section for this purpose which can be instantly attached to the present type of switch box and which is interlocked thereto against unauthorized removal or tampering. Each conduit section 61 is of rectangular or square cross section, as shown in Fig. 7, consisting of a back portion 62 of channel form, and a front portion 63, also of channel form, but of relatively shallow depth, which engages over the inwardly ofi'set marginal flanges 64 of the rear channel portion 62. At both ends of each length of conduit the metal of the upper and lower walls of the rear channel portion 62 is bent inwardly and then curved outwardly to form U-shaped flanges 65, which define outwardly facing grooves, as clearly shown in'Fig. 7. The back wall of this same channel portion 62 is also formed with a similar U-shaped flange 67 which forms a backwardly' facing groove. The front channel portion 63 is formed with an outwardly extending flange 69, formed by turning up a lip at the end of the stamping For receiving the ends of the conduit sections 61, the two side walls of the switch box 11 have relatively wide slots 71 cut therein, I

these slots extending back from the front edges of the side walls to points adjacent the back wall of the box, as shown in Fig. 6. In mounting the switch boxes on the panel they are placed. in a horizontal row with slots 71 of adjacent boxes alining and with the boxes ieo spaced the length of a conduit section apart.

\Vith the hinged covers of adjacent boxes swung down to open position, as illustrated by the central box in Figure 1, a condult section can be readily interconnected between adjacent boxes by merely sliding the ends of the conduit back into the slotted openings 71 of the boxes, with the U-shaped flanges embracing and interlocking with the upper and lower edges of the openings. The rear flange 67 at each end of the conduit section embraces and interlocks with the side wall 22 of the box at the rear end of the slot T1. If desired, a cap screw or bolt 72 may be extended through alined openings 73 in the U-shaped flange 67 and in the side wall The outer flange 69 of the conduit section is so formed that in swinging the hinge cover up into closed position the marginal flange 25 thereof will engage over the outer side of the conduit flange 69 and thereby interlock the end of the conduit section against removal from the box.

It will thus be seen that the foregoing construction ailords interlocking conduit sec tions which can be quickly and easily applied to and removed from the switch boxes by merely sliding the same into and out of slots in the box walls, and which when in mounted position are positively interlocked to ad o1ning boxes without the intervention of screws, bolts or other objectionable attaching means. At the end box of the series where no conduit section extends from one side wall thereof, the opening in this side wall can be closed by a suitable closure plate having U-shaped marginal flanges, similar to the flanges 5 and 67, for embracing the edges of the slotted opening. The side and bottonrwalls of the box are preferably provided wlth the usual knock-out plugs therein for receivlng the ends of ordinary circular conduit.

lVhat I claim as my invention and desire to secure by Letters Patent, is

1. In switch apparatus of the class described, a housing having an opening therein. a fuse mounting in said housing accessible through said opening, a switch in the housing and in circuit with said fuse mounting, a pivotally supported switch operating shaft bent to provide a crank portion within the housing and a handle portion outside of the housing, an operating connection between the switch and the crank portion of the shaft, a closure plate mounted on the housing for movement into positions to cover and uncover said opening, and a member carried by the plate and disposed and adapted for cooperation with the crank portion of the shaft for locking the switch open when the plate is in full open position, said member intersecting the path of movement of the crank )OltiOll of the shaft in switch closing direction when the plate has been moved in closing direction into a position slightly be yond switch locking position.

2. In switch apparatus of the class described, a housing having an opening therein, a fuse mounting in said housing accessible through said opening, a switch in the housing and in circuit with said fuse mounting, a pivotally supported switch operating shaft bent to provide a crank portion within the housing and a handle portion outside of the housing, an operating connection between the switch and the crank portion of the shaft, a closure plate mounted on the housing for movement into positions to cover and uncover said opening, and a member carried by the plate and disposed and adapted to intersect the path of movement of the crank portion of the shaft in switch closing direction in one plane when the plate is in full open position for locking the switch open, said member intersecting the path of movement of the crank portion of the shaft in switch closing direction in a second plane substantially at right angles to the first plane when the plate has been moved in closing direction into a position slightly beyond switch locking position.

3. In switch apparatus of the class described, a housing having an opening therein, a fuse mounting in the housing accessible through said opening, a switch in the housing and in circuit with said fuse mounting, a pivotally supportedswitch operating shaft bent to provide a crank portion within the housing and a handle portion outside of the housing, an operating connection between the switch and the crank portion of the shaft, a closure plate slidably mounted on the housing for movement at right angles to the shaft into positions to cover and uncover the opening, and a lug carried by the plate and projecting into the housing substantially at right angles to the shaft, said lug having two opcrative elements disposed substantially in rectangular relation, one of said elements locking the crank portion of the shaft against movement in switch closing direction when the plate is in full open position, and the other element extending transversely of the crank portion of the shaft in all positions thereof when the plate is moved in closing direction beyond switch locking position.

f. In switch apparatus of the class described, a housing having an opening therein, a fuse mounting in the housing accessible through said opening, a switch in the housing and in circuit with said fuse mounting, a pivot-ally supported switch operating shaft bent to provide a crank portion within the housing and a handle portion outside of the housing, an operating connection between the switch and the crank portion of the shaft, a closure plate slidably mounted on the housing for movement at right angles to the shaft into positions to cover and uncover the opening, and a lug carried by the plate and projecting into the housing substantially at right angles to the shaft, said lug corresponding in length to approximately the distance between the crank portion of the shaft and the plate when said shaft is in full open switch position, the inner end of the lug intersecting the path of movement of the crank portion of the shaft in switch closing direction when the switch and the plate are both in full open position.

DON ROSS FURNAS. 

